JP2024157843A - Method for manufacturing liquid crystal optical element - Google Patents

Abstract

[Problem] Peeling of a liquid crystal film is suppressed. [Solution] According to one embodiment, a method for manufacturing a liquid crystal optical element includes preparing a liquid crystal film having cholesteric liquid crystals, preparing a transparent substrate having at least a main surface made of an inorganic material, applying a solution containing a silane coupling agent to the main surface of the transparent substrate, laminating the liquid crystal film on the silane coupling agent, and heating the silane coupling agent. [Selected Figure] Figure 7

Description

An embodiment of the present invention relates to a method for manufacturing a liquid crystal optical element.

For example, a liquid crystal polarization grating using a liquid crystal material has been proposed. In such a liquid crystal polarization grating, it is necessary to adjust parameters such as the grating period, the refractive index anisotropy Δn of the liquid crystal layer (the difference between the refractive index ne of the liquid crystal layer for extraordinary light and the refractive index no for ordinary light), and the thickness d of the liquid crystal layer.

Special table 2017-522601 publication

The purpose of the embodiment is to provide a method for manufacturing a liquid crystal optical element that can suppress peeling of the liquid crystal film.

A method for producing a liquid crystal optical element according to an embodiment of the present invention includes the steps of:
A liquid crystal film having a cholesteric liquid crystal is prepared.
A transparent substrate is prepared, at least the main surface of which is made of an inorganic material;
A solution containing a silane coupling agent is applied to the main surface of the transparent substrate;
Laminating the liquid crystal film to the silane coupling agent;
The silane coupling agent is heated.

FIG. 1 is a cross-sectional view that illustrates a liquid crystal optical element 100 . FIG. 2 is a diagram for explaining an example of the cholesteric liquid crystal CL contained in the liquid crystal film 3. As shown in FIG. FIG. 3 is a plan view that illustrates the liquid crystal optical element 100. As shown in FIG. FIG. 4 shows an example of the main materials constituting the liquid crystal material. FIG. 5 is a diagram for explaining the process of forming the liquid crystal film 3. As shown in FIG. FIG. 6 is a diagram for explaining an example of a process for preparing a liquid crystal film. FIG. 7 is a diagram for explaining an example of a method for manufacturing the liquid crystal optical element 100. As shown in FIG. FIG. 8 is a diagram for explaining another example of the process of preparing a liquid crystal film. FIG. 9 is a diagram for explaining another example of the method for manufacturing the liquid crystal optical element 100. In FIG. FIG. 10 is a diagram showing a schematic chemical structure of a silane coupling agent. FIG. 11 is a diagram showing an example of a silane coupling agent. FIG. 12 is a diagram showing another example of the silane coupling agent.

The present embodiment will be described below with reference to the drawings. Note that the disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily conceive of while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematic in terms of width, thickness, shape, etc. of each part compared to the actual embodiment in order to make the explanation clearer, but they are merely an example and do not limit the interpretation of the present invention. In addition, in this specification and each figure, components that perform the same or similar functions as those described above with respect to the previous figures are given the same reference numerals, and duplicate detailed explanations may be omitted as appropriate.

In addition, in the drawings, to facilitate understanding, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are shown as necessary. The direction along the Z-axis is referred to as the Z direction or first direction A1, the direction along the Y-axis is referred to as the Y direction or second direction A2, and the direction along the X-axis is referred to as the X direction or third direction A3. The plane defined by the X-axis and Y-axis is referred to as the X-Y plane, the plane defined by the X-axis and Z-axis is referred to as the X-Z plane, and the plane defined by the Y-axis and Z-axis is referred to as the Y-Z plane.

FIG. 1 is a cross-sectional view that illustrates a liquid crystal optical element 100 .
The liquid crystal optical element 100 includes a transparent substrate 1 , an adhesive layer 2 , and a liquid crystal film 3 .

The transparent substrate 1 is, for example, made of a transparent glass plate or a transparent synthetic resin plate. The transparent substrate 1 may be, for example, made of a flexible transparent synthetic resin plate. The transparent substrate 1 may have any shape. For example, the transparent substrate 1 may be curved.

In this specification, "light" includes visible light and invisible light. For example, the lower limit of the visible light range is 360 nm or more and 400 nm or less, and the upper limit of the visible light range is 760 nm or more and 830 nm or less. Visible light includes a first component (blue component) in a first wavelength band (e.g., 400 nm to 500 nm), a second component (green component) in a second wavelength band (e.g., 500 nm to 600 nm), and a third component (red component) in a third wavelength band (e.g., 600 nm to 700 nm). Invisible light includes an ultraviolet wavelength band that is shorter than the first wavelength band, and an infrared wavelength band that is longer than the third wavelength band.
In this specification, "transparent" preferably means colorless transparency, however, "transparent" may also mean translucent or colored transparency.

The transparent substrate 1 is formed in a flat plate shape along the X-Y plane, and has a main surface (outer surface) F1, a main surface (inner surface) F2, and a side surface SS. The main surface F1 and the main surface F2 are surfaces that are approximately parallel to the X-Y plane, and face each other in the first direction A1. The side surface SS is a surface that extends along the first direction A1. In the example shown in FIG. 1, the side surface SS is a surface that is approximately parallel to the X-Z plane, but the side surface SS includes a surface that is approximately parallel to the Y-Z plane.

The adhesive layer 2 is disposed on the main surface F2.

The liquid crystal film 3 is adhered to the transparent substrate 1 via an adhesive layer 2. As shown enlarged and schematic, the liquid crystal film 3 contains cholesteric liquid crystal CL. The cholesteric liquid crystal CL has a helical axis AX that is substantially parallel to the first direction A1, and also has a helical pitch P along the first direction A1. The helical pitch P indicates one period of the helix (the layer thickness along the helical axis AX required for the liquid crystal molecules to rotate 360 degrees).

Such a liquid crystal film 3 is configured to reflect circularly polarized light in a selective reflection band determined according to the helical pitch P and the refractive index anisotropy Δn of the liquid crystal film 3, out of the light LTi incident on the liquid crystal optical element 100. Note that in this specification, "reflection" in the liquid crystal film 3 involves diffraction within the liquid crystal film 3.

The liquid crystal film 3 has a reflecting surface 3R that reflects circularly polarized light corresponding to the rotation direction of the cholesteric liquid crystal CL within the selective reflection band. The reflecting surface 3R is inclined with respect to the X-Y plane. Note that in this specification, the circularly polarized light may be strictly circularly polarized light or may be circularly polarized light that approximates elliptically polarized light.

In the example shown in FIG. 1, the liquid crystal film 3 is configured to reflect a portion of the light LTi incident from the main surface F1 side toward the transparent substrate 1.

In the liquid crystal optical element 100, a liquid crystal film having another cholesteric liquid crystal may be laminated on the liquid crystal film 3 shown in FIG. 1. The other cholesteric liquid crystal may be, for example, a cholesteric liquid crystal having a helical pitch different from the helical pitch P, or a cholesteric liquid crystal that is rotated in the opposite direction to the rotation direction of the cholesteric liquid crystal CL shown in the figure.

Next, the optical action of the liquid crystal optical element 100 shown in FIG. 1 will be described.

The light LTi incident on the liquid crystal optical element 100 includes, for example, visible light, ultraviolet light, and infrared light.
1, for ease of understanding, it is assumed that the light LTi is incident approximately perpendicularly to the transparent substrate 1. The angle of incidence of the light LTi with respect to the transparent substrate 1 is not particularly limited.

The light LTi passes through the transparent substrate 1 and enters the liquid crystal film 3. The liquid crystal film 3 reflects a part of the light LTi at the reflecting surface 3R and transmits the remaining light LTt. The reflected light LTr is circularly polarized light with a wavelength λ.
In one example, the light LTr is left-handed circularly polarized light in the infrared wavelength band, and the light LTt includes right-handed circularly polarized light in the infrared wavelength band in addition to visible light and ultraviolet light.

The approach angle θ of the light LTr reflected by the liquid crystal film 3 is set to satisfy the optical waveguide condition. The approach angle θ here corresponds to an angle equal to or greater than the critical angle at which total reflection occurs at the interface between the liquid crystal film 3 and the air. The approach angle θ indicates the angle with respect to the normal N of the transparent substrate 1.

When the transparent substrate 1 and the liquid crystal film 3 have the same refractive index, the laminate of these can become a single light-guiding element. In this case, the light LTr is repeatedly reflected at the interface between the transparent substrate 1 and the air, and at the interface between the liquid crystal film 3 and the air, and is guided toward the side surface SS.

Such a liquid crystal optical element 100 can be used, for example, as a light guide element of a solar cell device. The solar cell device includes the liquid crystal optical element 100 and a solar cell PV shown by a dotted line in FIG. 1. The solar cell PV is disposed so as to face the side surface SS. The solar cell PV can receive light LTr emitted from the side surface SS and generate electricity.

Note that, although an example in which infrared light is reflected by the liquid crystal film 3 has been described here, the liquid crystal film 3 may be configured to reflect visible light, ultraviolet light, or light in multiple wavelength bands.

Figure 2 is a diagram illustrating an example of the cholesteric liquid crystal CL contained in the liquid crystal film 3.

In FIG. 2, the liquid crystal film 3 is shown enlarged in the first direction A1. For simplicity, one liquid crystal molecule LM out of multiple liquid crystal molecules located on the same plane parallel to the X-Y plane is shown as the liquid crystal molecule that constitutes the cholesteric liquid crystal CL. The orientation direction of the illustrated liquid crystal molecule LM corresponds to the average orientation direction of multiple liquid crystal molecules located on the same plane.

Focusing on one cholesteric liquid crystal CL surrounded by a dotted line, the cholesteric liquid crystal CL is composed of multiple liquid crystal molecules LM that are stacked in a spiral shape along the first direction A1 while rotating. The multiple liquid crystal molecules LM include a liquid crystal molecule LM11 that is located near the interface between the adhesive layer 2 and the liquid crystal film 3.

2, the alignment directions of the cholesteric liquid crystals CL adjacent to each other along the second direction A2 are different from each other. In addition, the spatial phases of the cholesteric liquid crystals CL adjacent to each other along the second direction A2 are different from each other.
The alignment directions of the liquid crystal molecules LM11 adjacent to each other along the second direction A2 are different from each other. The alignment directions of the liquid crystal molecules LM11 change continuously along the second direction A2.

The reflecting surface 3R of the liquid crystal film 3, indicated by the dashed line in the figure, is inclined with respect to the XY plane. The angle θα between the reflecting surface 3R and the XY plane is an acute angle. The reflecting surface 3R corresponds to a surface on which the orientation direction of the liquid crystal molecules LM is uniform, or a surface on which the spatial phase is uniform (an equiphase surface).

Such a liquid crystal film 3 is hardened with the alignment direction of the liquid crystal molecules LM fixed. In other words, the alignment direction of the liquid crystal molecules LM is not controlled in response to an electric field. For this reason, the liquid crystal optical element 100 does not include electrodes for forming an electric field in the liquid crystal film 3.

Generally, in a liquid crystal film 3 having a cholesteric liquid crystal CL, the selective reflection band Δλ for perpendicularly incident light is expressed by the following formula (1) based on the helical pitch P of the cholesteric liquid crystal CL and the refractive index anisotropy Δn (the difference between the refractive index ne for extraordinary light and the refractive index no for ordinary light) of the liquid crystal film 3.
Δλ=Δn*P…(1)
A specific wavelength range of the selective reflection band Δλ is a range from (no*P) to (ne*P).

The central wavelength λm of the selective reflection band Δλ is expressed by the following formula (2) based on the helical pitch P of the cholesteric liquid crystal CL and the average refractive index nav (=(ne+no)/2) of the liquid crystal film 3.
λm=nav*P…(2)
FIG. 3 is a plan view that illustrates the liquid crystal optical element 100. As shown in FIG.
3 shows an example of the spatial phase of the cholesteric liquid crystal CL. The spatial phase shown here is shown as the orientation direction of the liquid crystal molecule LM11 located near the adhesive layer 2 among the liquid crystal molecules LM contained in the cholesteric liquid crystal CL.

The alignment directions of the liquid crystal molecules LM11 of the cholesteric liquid crystals CL aligned along the second direction A2 are different from each other, that is, the spatial phases of the cholesteric liquid crystals CL are different along the second direction A2.
On the other hand, the alignment directions of the liquid crystal molecules LM11 of the cholesteric liquid crystals CL aligned along the third direction A3 are substantially the same, that is, the spatial phases of the cholesteric liquid crystals CL are substantially the same in the third direction A3.

In particular, when focusing on the cholesteric liquid crystal CL aligned in the second direction A2, the alignment direction of each liquid crystal molecule LM11 differs by a certain angle. In other words, the alignment direction of the multiple liquid crystal molecules LM11 aligned along the second direction A2 changes linearly. Therefore, the spatial phase of the multiple cholesteric liquid crystals CL aligned along the second direction A2 changes linearly along the second direction A2. As a result, a reflecting surface 3R that is inclined with respect to the X-Y plane is formed, as in the liquid crystal film 3 shown in FIG. 2. Here, "linearly changes" indicates that, for example, the amount of change in the alignment direction of the liquid crystal molecule LM11 is expressed by a linear function. Note that the alignment direction of the liquid crystal molecule LM11 here corresponds to the long axis direction of the liquid crystal molecule LM11 in the X-Y plane.

Here, the interval between two liquid crystal molecules LM11 when the alignment direction of the liquid crystal molecules LM11 changes by 180 degrees along the second direction A2 in one plane is defined as the period T. In FIG. 3, DP indicates the rotation direction of the liquid crystal molecules LM11. The inclination angle θα of the reflecting surface 3R shown in FIG. 2 is appropriately set by the period T and the helical pitch P. In one example, the period T is 1000 nm to 3000 nm, and in another example, it is 300 nm to 700 nm.

Next, the liquid crystal film 3 will be described.
The liquid crystal film 3 is formed by polymerizing liquid crystal monomers having functional groups such as methacryl groups, acrylic groups, vinyl groups, and vinyl ether groups.
The liquid crystal material for forming the liquid crystal film 3 mainly contains a liquid crystal monomer, a polymerization initiator, and a solvent. When the liquid crystal film 3 contains the above-mentioned cholesteric liquid crystal CL, the liquid crystal material further contains a chiral dopant.

FIG. 4 shows an example of the main materials constituting the liquid crystal material.
The material M1 corresponds to an example of a liquid crystal monomer.
The material M2 corresponds to an example of a chiral dopant.
The material M3 corresponds to an example of a polymerization initiator.
The solvent may be, for example, hexane, cyclohexane, cyclohexanone, heptane, toluene, anisole, propylene glycol monomethyl ether acetate (PGMEA), or the like.

FIG. 5 is a diagram for explaining the process of forming the liquid crystal film 3. As shown in FIG.
First, the support substrate is cleaned (step ST1).
Then, an alignment film is formed on the support substrate (step ST2). The alignment film is formed by performing an alignment process (photo-alignment process) on the thin film formed on the support substrate. The alignment film formed by such an alignment process has an alignment axis of a predetermined pattern.
Then, the liquid crystal material prepared earlier is applied onto the alignment film (step ST3).
The liquid crystal material is then dried by reducing the pressure inside the chamber (step ST4). At this time, the pressure inside the chamber is set to 100 Pa or less, and the drying process is carried out for 2 minutes.
Then, the liquid crystal material is baked (step ST5). At this time, it is preferable that the temperature to which the liquid crystal material is heated does not exceed the NI point (Nematic-Isotropic transition temperature). Through this process, the liquid crystal molecules contained in the liquid crystal material are aligned in a predetermined direction according to the alignment axis of the alignment film. Furthermore, if the liquid crystal material contains a chiral dopant, the liquid crystal molecules are aligned in a helical shape, and a cholesteric liquid crystal phase is exhibited.
Then, the liquid crystal material is cooled to about room temperature (step ST6).

Then, the liquid crystal material is irradiated with ultraviolet light to harden it (step ST7). This forms a liquid crystal film 3 having cholesteric liquid crystal CL.

In the above example, the liquid crystal film 3 has cholesteric liquid crystal CL, but the liquid crystal film 3 may have nematic liquid crystal. By using a liquid crystal material that does not contain a chiral dopant as the liquid crystal material that forms the liquid crystal film 3, a liquid crystal film 3 having nematic liquid crystal can be formed.

FIG. 6 is a diagram for explaining an example of a process for preparing a liquid crystal film.
First, as shown in the upper part of Fig. 6, the liquid crystal film 3 is formed on the supporting substrate SUB via the alignment film AL. The process of forming the liquid crystal film 3 is as described with reference to Fig. 5.
6, the thermal peeling tape TP is adhered to the liquid crystal film 3. The thermal peeling tape TP may be adhered to the entire surface of the liquid crystal film 3, or may be adhered to only a part of the liquid crystal film 3.
6, the liquid crystal film 3 adhered to the thermal peeling tape TP is peeled off from the alignment film AL, thereby preparing the liquid crystal film 3.

Next, a method for manufacturing the liquid crystal optical element 100 will be described.

Figure 7 is a diagram illustrating an example of a manufacturing method for the liquid crystal optical element 100.

First, the transparent substrate 1 is prepared (step ST11). In the transparent substrate 1, at least the material forming the main surface F2 is an inorganic material.
For example, the transparent substrate 1 may be a glass substrate mainly made of silicon oxide (SiO ₂ ), such as soda-lime glass, borosilicate glass, or quartz glass.
Alternatively, as another example of the transparent substrate 1, a substrate in which an inorganic film such as silicon nitride (SiN) or silicon oxide (SiO ₂ ) is formed on the surface of a transparent resin such as acrylic, polyethylene terephthalate, polycarbonate, or polyvinyl chloride can be applied. In this case, the surface of the inorganic film corresponds to the main surface F2.

Next, a solution containing a silane coupling agent is applied to the main surface F2 of the transparent substrate 1 as the adhesive layer 2 (step ST12). The silane coupling agent is an organosilicon compound having an alkoxy group and a reactive functional group. The solution is an aqueous solution or an alcohol solution containing 0.1% by weight or more and 3.0% by weight or less of the silane coupling agent.
Then, the solution containing the silane coupling agent is dried (step ST13), thereby forming an adhesive layer 2 made of the silane coupling agent.

Next, the liquid crystal film 3 adhered to the heat peeling tape TP through the steps shown in FIGS. 5 and 6 is prepared, and the liquid crystal film 3 is laminated on the adhesive layer (silane coupling agent) 2 (step ST14).
Then, the thermal peeling tape TP is heated (step ST15). This heating reduces the adhesive strength of the thermal peeling tape TP.
Then, the heat peeling tape TP is peeled off from the liquid crystal film 3 (step ST16).

Next, the adhesive layer (silane coupling agent) 2 is heated (step ST17). As a result, the alkoxy groups of the silane coupling agent are chemically bonded to the inorganic material forming the main surface F2 of the transparent substrate 1, and the reactive functional groups of the silane coupling agent are chemically bonded to the functional groups remaining unreacted in the liquid crystal film 3.
In this way, the liquid crystal optical element 100 is manufactured.

The liquid crystal optical element 100 formed through the above steps has the liquid crystal film 3 chemically bonded to the transparent substrate 1 via the adhesive layer 2, which makes it possible to prevent the liquid crystal film 3 from peeling off or falling off from the transparent substrate 1.

The adhesive layer 2, which is a silane coupling agent, is transparent, and no interface due to differences in refractive index is formed between the transparent substrate 1 and the adhesive layer 2, or between the adhesive layer 2 and the liquid crystal film 3. This suppresses undesirable scattering and undesirable reflection inside the liquid crystal optical element 100. Therefore, when the liquid crystal optical element 100 is used as a light guide element, it is possible to suppress a decrease in light guide efficiency.

Also, alignment films formed from polyimide or the like may be colored. On the other hand, the liquid crystal optical element 100 manufactured by the above manufacturing method does not include an alignment film. Therefore, it is possible to provide a liquid crystal optical element 100 with high transparency.

In the manufacturing method described with reference to FIG. 7, the process of heating the thermal peeling tape TP and the process of heating the silane coupling agent are carried out separately. This is because the temperature range that promotes the chemical reaction of the silane coupling agent is significantly different from the temperature range that reduces the adhesive strength of the thermal peeling tape TP. If the temperature range that promotes the chemical reaction of the silane coupling agent is close to the temperature range that reduces the adhesive strength of the thermal peeling tape TP, the process of heating the thermal peeling tape TP in step ST15 may also serve as the process of heating the silane coupling agent. In this case, the heating process in step ST17 is not necessary.

Next, we will explain other manufacturing methods.

FIG. 8 is a diagram for explaining another example of the process of preparing a liquid crystal film.
First, as shown in the upper part of Fig. 8, the liquid crystal film 3 is formed on the supporting substrate SUB via the alignment film AL. The process of forming the liquid crystal film 3 is as described with reference to Fig. 5 .
Next, as shown in the middle part of FIG. 8, a roller RL is pressed against one end side of the liquid crystal film 3 .
8, the liquid crystal film 3 is wound around a roller RL, and the liquid crystal film 3 is peeled off from the alignment film AL, thereby preparing the liquid crystal film 3.

Next, a method for manufacturing the liquid crystal optical element 100 will be described.

Figure 9 is a diagram for explaining another example of a manufacturing method for the liquid crystal optical element 100.

First, a transparent substrate 1 is prepared (step ST21). As described above, the material forming at least the main surface F2 of the transparent substrate 1 is an inorganic material.

Next, a solution containing a silane coupling agent is applied to the main surface F2 of the transparent substrate 1 as the adhesive layer 2 (step ST22). The silane coupling agent is an organosilicon compound having an alkoxy group and a reactive functional group. The solution is an aqueous solution or an alcohol solution containing 0.1% by weight or more and 3.0% by weight or less of the silane coupling agent.
Then, the solution containing the silane coupling agent is dried (step ST23), thereby forming an adhesive layer 2 made of the silane coupling agent.

Subsequently, after the steps shown in FIG. 5 and FIG. 8 are performed to prepare the liquid crystal film 3 wound around the roller RL, a part of the liquid crystal film 3 is brought into contact with the adhesive layer (silane coupling agent) 2 (step ST24).
Then, the thermal peeling tape TP is heated (step ST15). This heating reduces the adhesive strength of the thermal peeling tape TP.
Then, the roller RL is rotated to transfer the liquid crystal film 3 onto the adhesive layer 2 (step ST26).

Next, the adhesive layer (silane coupling agent) 2 is heated (step ST26). As a result, the alkoxy groups of the silane coupling agent are chemically bonded to the inorganic material forming the main surface F2 of the transparent substrate 1, and the reactive functional groups of the silane coupling agent are chemically bonded to the functional groups remaining unreacted in the liquid crystal film 3.
In this way, the liquid crystal optical element 100 is manufactured.

Even when the above manufacturing method is applied, the same effects as those described above can be obtained.
In addition, the heating step for peeling the liquid crystal film 3 from the thermal peeling tape TP is not required.

Next, we will explain the silane coupling agents that can be used in this embodiment.

FIG. 10 is a diagram showing a schematic chemical structure of a silane coupling agent.
In the silane coupling agent, the alkoxy group OR that chemically bonds to the inorganic material that forms the main surface of the transparent substrate 1 is, for example, a methoxy group, an ethoxy group, or an acetyl group.
In the silane coupling agent, the reactive functional group Y that chemically bonds with the liquid crystal film 3 is, for example, an epoxy group, a styryl group, a mercapto group, an isocyanate group, a methacryl group, an acrylic group, or an amino group.

FIG. 11 is a diagram showing an example of a silane coupling agent.
In the illustrated examples, examples of silane coupling agents having an epoxy group, a styryl group, a mercapto group, and an isocyanate group as reactive functional groups are shown.

Examples of silane coupling agents having epoxy groups include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane.

An example of a silane coupling agent having a styryl group is p-styryltrimethoxysilane.

Examples of silane coupling agents having a mercapto group include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane.

An example of a silane coupling agent having an isocyanate group is 3-isocyanatepropyltriethoxysilane.

FIG. 12 is a diagram showing another example of the silane coupling agent.
In the illustrated example, a silane coupling agent having a methacryl group, an acrylic group, or an amino group as a reactive functional group is shown.

Examples of silane coupling agents having methacryl groups include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane.

An example of a silane coupling agent having an acrylic group is 3-acryloxypropyltrimethoxysilane.

Examples of silane coupling agents having an amino group include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane.

As described above, this embodiment can provide a method for manufacturing a liquid crystal optical element that can suppress peeling of the liquid crystal film.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents as set forth in the claims.

Reference Signs List 100: Liquid crystal optical element 1: Transparent substrate F1: Main surface F2: Main surface SS: Side surface 2: Adhesive layer 3: Liquid crystal film CL: Cholesteric liquid crystal 3R: Reflective surface

Claims (8)

A liquid crystal film having a cholesteric liquid crystal is prepared.
A transparent substrate is prepared, at least the main surface of which is made of an inorganic material;
A solution containing a silane coupling agent is applied to the main surface of the transparent substrate;
Laminating the liquid crystal film to the silane coupling agent;
Heating the silane coupling agent;
A method for manufacturing a liquid crystal optical element. The step of preparing the liquid crystal film includes:
A liquid crystal material including a liquid crystal monomer and a polymerization initiator is prepared;
An alignment film is formed on a supporting substrate;
The liquid crystal material is applied onto the alignment film;
The liquid crystal material is cured in a state where it exhibits a cholesteric liquid crystal phase to form the liquid crystal film;
A thermal release tape is adhered to the liquid crystal film;
peeling the liquid crystal film from the alignment film.
A method for producing the liquid crystal optical element according to claim 1 . After laminating the liquid crystal film onto the silane coupling agent,
heating the thermal release tape to peel the thermal release tape from the liquid crystal film;
A method for producing the liquid crystal optical element according to claim 2 . The method for manufacturing a liquid crystal optical element according to claim 3, wherein the step of heating the thermal peeling tape also serves as a step of heating the silane coupling agent. The step of preparing the liquid crystal film includes:
A liquid crystal material including a liquid crystal monomer and a polymerization initiator is prepared;
An alignment film is formed on a supporting substrate;
The liquid crystal material is applied onto the alignment film;
The liquid crystal material is cured in a state where it exhibits a cholesteric liquid crystal phase to form the liquid crystal film;
wrapping the liquid crystal film around a roller and peeling the liquid crystal film off the alignment film.
A method for producing the liquid crystal optical element according to claim 1 . The step of laminating the liquid crystal film on the silane coupling agent includes transferring the liquid crystal film wound around the roller onto the silane coupling agent.
A method for producing the liquid crystal optical element according to claim 5 . the silane coupling agent is an organosilicon compound having an alkoxy group that chemically bonds with the inorganic material forming the main surface and a reactive functional group that chemically bonds with the liquid crystal film;
The method for producing a liquid crystal optical element according to claim 1, wherein the reactive functional group is any one of an epoxy group, a styrene group, a methacryl group, an acrylic group, an amino group, a mercapto group, and an isocyanate group. The method for producing a liquid crystal optical element according to claim 1, wherein the solution is an aqueous solution or an alcohol solution containing 0.1% by weight or more and 3.0% by weight or less of the silane coupling agent.

Images